Java™ Platform
Standard Ed. 6

java.io
Class StringWriter

java.lang.Object
  extended by java.io.Writer
      extended by java.io.StringWriter
All Implemented Interfaces:
Closeable, Flushable, Appendable

public class StringWriter
extends Writer

A character stream that collects its output in a string buffer, which can then be used to construct a string.

Closing a StringWriter has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Since:
JDK1.1

Field Summary
 
Fields inherited from class java.io.Writer
lock
 
Constructor Summary
StringWriter()
          Create a new string writer using the default initial string-buffer size.
StringWriter(int initialSize)
          Create a new string writer using the specified initial string-buffer size.
 
Method Summary
 StringWriter append(char c)
          Appends the specified character to this writer.
 StringWriter append(CharSequence csq)
          Appends the specified character sequence to this writer.
 StringWriter append(CharSequence csq, int start, int end)
          Appends a subsequence of the specified character sequence to this writer.
 void close()
          Closing a StringWriter has no effect.
 void flush()
          Flush the stream.
 StringBuffer getBuffer()
          Return the string buffer itself.
 String toString()
          Return the buffer's current value as a string.
 void write(char[] cbuf, int off, int len)
          Write a portion of an array of characters.
 void write(int c)
          Write a single character.
 void write(String str)
          Write a string.
 void write(String str, int off, int len)
          Write a portion of a string.
 
Methods inherited from class java.io.Writer
write
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

StringWriter

public StringWriter()
Create a new string writer using the default initial string-buffer size.


StringWriter

public StringWriter(int initialSize)
Create a new string writer using the specified initial string-buffer size.

Parameters:
initialSize - The number of char values that will fit into this buffer before it is automatically expanded
Throws:
IllegalArgumentException - If initialSize is negative
Method Detail

write

public void write(int c)
Write a single character.

Overrides:
write in class Writer
Parameters:
c - int specifying a character to be written

write

public void write(char[] cbuf,
                  int off,
                  int len)
Write a portion of an array of characters.

Specified by:
write in class Writer
Parameters:
cbuf - Array of characters
off - Offset from which to start writing characters
len - Number of characters to write

write

public void write(String str)
Write a string.

Overrides:
write in class Writer
Parameters:
str - String to be written

write

public void write(String str,
                  int off,
                  int len)
Write a portion of a string.

Overrides:
write in class Writer
Parameters:
str - String to be written
off - Offset from which to start writing characters
len - Number of characters to write

append

public StringWriter append(CharSequence csq)
Appends the specified character sequence to this writer.

An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation

     out.write(csq.toString()) 

Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

Specified by:
append in interface Appendable
Overrides:
append in class Writer
Parameters:
csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.
Returns:
This writer
Since:
1.5

append

public StringWriter append(CharSequence csq,
                           int start,
                           int end)
Appends a subsequence of the specified character sequence to this writer.

An invocation of this method of the form out.append(csq, start, end) when csq is not null, behaves in exactly the same way as the invocation

     out.write(csq.subSequence(start, end).toString()) 

Specified by:
append in interface Appendable
Overrides:
append in class Writer
Parameters:
csq - The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".
start - The index of the first character in the subsequence
end - The index of the character following the last character in the subsequence
Returns:
This writer
Throws:
IndexOutOfBoundsException - If start or end are negative, start is greater than end, or end is greater than csq.length()
Since:
1.5

append

public StringWriter append(char c)
Appends the specified character to this writer.

An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation

     out.write(c) 

Specified by:
append in interface Appendable
Overrides:
append in class Writer
Parameters:
c - The 16-bit character to append
Returns:
This writer
Since:
1.5

toString

public String toString()
Return the buffer's current value as a string.

Overrides:
toString in class Object
Returns:
a string representation of the object.

getBuffer

public StringBuffer getBuffer()
Return the string buffer itself.

Returns:
StringBuffer holding the current buffer value.

flush

public void flush()
Flush the stream.

Specified by:
flush in interface Flushable
Specified by:
flush in class Writer

close

public void close()
           throws IOException
Closing a StringWriter has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Specified by:
close in interface Closeable
Specified by:
close in class Writer
Throws:
IOException - If an I/O error occurs

Java™ Platform
Standard Ed. 6

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For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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